Semiconductor device, manufacturing method for semiconductor device, electronic component, circuit substrate, and electronic apparatus

ABSTRACT

A semiconductor device includes: a semiconductor substrate including a first face and a second face on a side opposite to the first face; an external connection terminal formed on the first face of the semiconductor substrate; a first electrode formed on the first face of the semiconductor substrate and electrically connected to the external connection terminal; an electronic element formed on or above the second face of the semiconductor substrate; a second electrode electrically connected to the electronic element and having a top face and a rear face; a groove portion formed on the second face of the semiconductor substrate and having a bottom face including at least part of the rear face of the second electrode; and a conductive portion formed in the groove portion and electrically connected to the rear face of the second electrode.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No.2005-168373, filed Jun. 8, 2005, the contents of which are incorporatedherein by reference.

BACKGROUND

1. Technical Field

The present invention relates to a semiconductor device, a manufacturingmethod for a semiconductor device, an electronic component, a circuitsubstrate, and an electronic apparatus.

2. Related Art

Recently, electronic components including surface acoustic wave elements(hereinafter abbreviated as ‘SAW element’) as, for example, resonatorsand band filters are used in electronic apparatuses such as mobiletelephones and television receivers.

Japanese Unexamined Patent Application, First Publication No.2002-290184 and Japanese Unexamined Patent Application, FirstPublication No. 2002-290200 disclose examples of techniques relating toelectronic components including SAW elements.

Japanese Unexamined Patent Application, First Publication No.2002-290184 discloses a technique relating to an electronic componentpackage in which a SAW element and an integrated circuit driving andcontrolling the SAW element are arranged in the same space.

Japanese Unexamined Patent Application, First Publication No.2002-290200 discloses a technique relating to an electronic componentpackage in which a SAW element is packaged on a first substrate and anintegrated circuit is packaged on a second substrate.

Requests to miniaturize electronic apparatuses in which electroniccomponents including SAW elements are packaged are being accompanied byrequests to miniaturize electronic components including semiconductordevices and electronic apparatuses, on which electronic elements such asSAW elements are packaged.

However, the configuration disclosed in Japanese Unexamined PatentApplication, First Publication No. 2002-290184 is difficult tominiaturize, since the SAW element and the integrated circuit arearranged in parallel.

Similarly, the configuration disclosed in Japanese Unexamined PatentApplication, First Publication No. 2002-290200 is difficult to make thin(small), since the first substrate on which the SAW element is packaged,and the second substrate on which the integrated circuit is packaged,are superimposed.

In addition to electronic components including SAW elements, there arealso demands for smaller electronic components including electronicelements which require airtight sealing, such as crystal oscillators,and piezoelectric oscillators, and piezoelectric tuning-forks.

SUMMARY

An advantage of some aspects of the invention is to provide asemiconductor device, a manufacturing method for a semiconductor device,an electronic component, a circuit substrate, and an electronicapparatus, which can be made smaller, thinner, and achieve higherperformance.

A first aspect of the invention provides a semiconductor deviceincludes: a semiconductor substrate including a first face and a secondface on a side opposite to the first face; an external connectionterminal formed on the first face of the semiconductor substrate; afirst electrode formed on the first face of the semiconductor substrateand electrically connected to the external connection terminal; anelectronic element formed on or above the second face of thesemiconductor substrate; a second electrode electrically connected tothe electronic element and having a top face and a rear face; a grooveportion formed on the second face of the semiconductor substrate andhaving a bottom face including at least part of the rear face of thesecond electrode; and a conductive portion formed in the groove portionand electrically connected to the rear face of the second electrode.

According to the semiconductor device of the first aspect of theinvention, since the conductive portion is formed in the groove portionhaving a bottom face including at least part of the rear face of thesecond electrode, the second electrode and the electronic element can beelectrically connected via the conductive portion.

Furthermore, since the first electrode is electrically connected to theexternal connection terminal, the overall semiconductor device which canbe connected to an external apparatus (e.g., a circuit substrate) andthe similar, can be made smaller and thinner, and its performance can beincreased.

It is preferable that the semiconductor device of the first aspect ofthe invention further include: an interconnection formed on the firstface of the semiconductor substrate and electrically connected to thefirst electrode and the external connection terminal; and astress-absorbing layer formed between the semiconductor substrate andthe external connection terminal.

According to the semiconductor device of the first aspect of theinvention, since the semiconductor device is provided with theinterconnection by connecting the first electrode to the externalconnection terminal via the interconnection, the shape and arrangementof the external connection terminal can be set more freely.

In addition, the stress-absorbing layer increases the reliability of theconnection between the semiconductor device and external apparatuses andthe similar.

It is preferable that the semiconductor device of the first aspect ofthe invention further include: a metal film formed on the top face ofthe second electrode and including an identical material of theinterconnection.

In the semiconductor device of the first aspect of the invention, amaterial which is highly resistant to corrosion is generally used forthe interconnection.

Therefore, by forming the metal film from the identical material of theinterconnection on the top face of the second electrode, corrosion ofthe top face of the second electrode can be prevented, and thegeneration of electrical malfunctions can be prevented.

It is preferable that the semiconductor device of the first aspect ofthe invention further include: a connection electrode formed on thesecond face of the semiconductor substrate and electrically connected tothe conductive portion.

In the semiconductor device according to the first aspect of theinvention, by providing the connection electrode electrically connectedto the conductive portion (e.g., by forming a connection electrodecorresponding to the electrode shape of the electronic element), thedegree of freedom when designing the connection structure of theelectronic element can be increased.

A second aspect of the invention provides manufacturing method for asemiconductor device includes: preparing a semiconductor substrateincluding a first face and a second face on a side opposite to the firstface; forming a first electrode on the first face of the semiconductorsubstrate; forming a second electrode having a top face and a rear faceon the first face of the semiconductor substrate; forming on the firstface of the semiconductor substrate an interconnection electricallyconnected to the first electrode; electrically connecting the firstelectrode to the interconnection by forming an external connectionterminal connected to the interconnection on the first face of thesemiconductor substrate; forming a stress-absorbing layer between thesemiconductor substrate and the external connection terminal; forming agroove portion having a bottom face including at least part of the rearface of the second electrode, on the second face of the semiconductorsubstrate; forming an insulating film on side wall of the grooveportion; and forming in the groove portion a conductive portionelectrically connecting an electronic element to the second electrode.

According to the manufacturing method for semiconductor device of thesecond aspect of the invention, since the groove portion is formed fromthe second face of the semiconductor substrate on which the secondelectrode is not formed, it becomes easier to form the conductiveportion for electrically connecting to the second electrode.

Since the conductive portion for electrically connecting to the secondelectrode is formed after forming the insulating film on the side wallsof the grooves section, the conductive portion and the semiconductorsubstrate can be reliably insulated.

This enables a voltage to be applied accurately from the secondelectrode to the electronic element via the conductive portion, wherebythe electronic element can be driven reliably.

It is preferable that, in the manufacturing method for the semiconductordevice of the second aspect of the invention, photolithography andetching be used in the forming of the groove portion.

According to the manufacturing method for semiconductor device of thesecond aspect of the invention, by using photolithography and etching,the groove portion can be precisely formed in the semiconductorsubstrate.

It is preferable that the manufacturing method for the semiconductordevice of the second aspect of the invention further include: forming aconnection electrode electrically connected to the conductive portion,on the second face of the semiconductor substrate, and connectionelectrode and the conductive portion be formed in one operation.

In the manufacturing method for semiconductor device according to thesecond aspect of the invention, by forming the connection electrode andthe conductive portion in one operation, the semiconductor device can bemanufactured efficiently and the manufacturing cost can be reduced.

It is preferable that the manufacturing method for the semiconductordevice of the second aspect of the invention further include: forming aplurality of semiconductor devices on the semiconductor substrate in oneoperation; dividing each of the semiconductor devices by cutting thesemiconductor substrate; and obtaining a plurality of individualsemiconductor devices.

According to the manufacturing method for semiconductor device of thesecond aspect of the invention, a plurality of semiconductor devices areformed simultaneously on the substrate and the substrate is then cutinto individual semiconductor devices, it is possible to reduce themanufacturing cost of the semiconductor device.

A third aspect of the invention provides a electronic componentincludes: a semiconductor substrate including a first face and a secondface on a side opposite to the first face; an external connectionterminal formed on the first face of the semiconductor substrate; afirst electrode formed on the first face of the semiconductor substrateand electrically connected to the external connection terminal; anelectronic element formed on or above the second face of thesemiconductor substrate; a second electrode electrically connected tothe electronic element and having a top face and a rear face; a grooveportion formed on the second face of the semiconductor substrate andhaving a bottom face including at least part of the rear face of thesecond electrode; a conductive portion formed in the groove portion andelectrically connected to the rear face of the second electrode; and asealing member sealing the electronic element.

According to the electronic component of the third aspect of theinvention, by forming the electronic element on the second face of thesemiconductor substrate and electrically connecting the electronicelement to the conductive portion, the second electrode can beelectrically connected to the electronic element via the conductiveportion.

Furthermore, since the first electrode is electrically connected to theexternal connection terminal, the overall electronic component which canbe connected to external apparatuses and the similar can be made smallerand thinner.

Moreover, since the electronic element is sealed by the sealing member,the overall electronic component can be made smaller and thinner whileenabling the electronic element to be driven reliably.

It is preferable that, in the electronic component of the third aspectof the invention, the sealing member be spaced from the second face ofthe semiconductor substrate, and include a facing face facing the secondface of the semiconductor substrate, and the electronic element isformed on the facing face.

According to the electronic component of the third aspect of theinvention, since the electronic element is formed on a facing face ofthe sealing member, the electronic element can be sealed by electricallyconnecting the electronic element to the conductive portion.

Therefore, a sealed electronic component can be obtained with a simpleconfiguration.

It is preferable that the electronic component of the third aspect ofthe invention further include: a supporting substrate supporting theelectronic element, and the sealing member spaced from the second faceof the semiconductor substrate, and the supporting substrate be arrangedbetween the sealing member and the semiconductor substrate.

According to the electronic component of the third aspect of theinvention, since the electronic element is formed on the supportingsubstrate, it is possible to electrically connect the electronic elementand the conductive portion, while the supporting substrate supports theelectronic element.

This enables the electronic element to be driven reliably.

It is preferable that the electronic component of the third aspect ofthe invention further include: a supporting substrate spaced from thesecond face of the semiconductor substrate and supporting the electronicelement, and the sealing member seals the electronic element supportedby the supporting substrate and include an electronic element electrodeelectrically connected to the electronic element.

According to the electronic component of the third aspect of theinvention, since the electronic element supported by the supportingsubstrate is sealed by the sealing member, the electronic element can bemade smaller and thinner, and driven reliably, by connecting theelectronic element electrode formed on the sealing member to theconductive portion.

It is preferable that the electronic component of the third aspect ofthe invention further include: a connection electrode formed on thesecond face of the semiconductor substrate and electrically connectingthe conductive portion to the electronic element.

According to the electronic component of the third aspect of theinvention, by forming a connection electrode which, for example,corresponds to the electrode shape of the electronic element, a reliablystate of conduction can be obtained between the electronic element andthe second electrode.

A fourth aspect of the invention provides a circuit substrate on whichthe above described electronic component is packaged.

According to the circuit substrate of the fourth aspect of theinvention, it is possible to provide a circuit substrate on which asmall and thin electronic component is packaged (e.g., a printed wiringboard).

Therefore, even if this circuit substrate is packaged in an electronicapparatus or the similar, an increase in the size of the electronicapparatus can be prevented.

A fifth aspect of the invention provides an electronic apparatus inwhich the above described electronic component is packaged.

According to the electronic apparatus of the fifth aspect of theinvention, it is possible to provide an electronic apparatus in which asmall and thin electronic component is packaged.

This enables the electronic apparatus to be made smaller.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a semiconductor device according toan embodiment of this invention.

FIG. 2 is a plan view from the arrow A of the semiconductor device ofFIG. 1.

FIG. 3 is a plan view from the arrow B of the semiconductor device ofFIG. 1.

FIGS. 4A to 4C are cross-sectional views of a manufacturing method forsemiconductor device according to an embodiment of this invention.

FIGS. 5A to 5C are cross-sectional views of a manufacturing method forsemiconductor device according to an embodiment of this invention.

FIG. 6 is a cross-sectional view of a manufacturing method forsemiconductor device according to an embodiment of this invention.

FIG. 7 is a cross-sectional view of an electronic component according toan embodiment of this invention.

FIG. 8 is a plan view of an electrode of the electronic component ofFIG. 7.

FIG. 9 is a cross-sectional view of an electronic component according toa second embodiment of this invention.

FIG. 10 is a cross-sectional view of an electronic component accordingto a third embodiment of this invention.

FIG. 11 is a cross-sectional view of an electronic component accordingto a fourth embodiment of this invention.

FIG. 12 is a view of an electronic apparatus in which an electroniccomponent of this invention is packaged.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiment of Semiconductor Device

Subsequently, an embodiment of a semiconductor device of this inventionwill be explained with reference to FIGS. 1 to 6.

As shown in FIG. 1, a semiconductor device 1 according to thisembodiment includes a silicon substrate 10 (semiconductor substrate) anda connector 20.

The connector 20 is formed on a first face 10 a of the silicon substrate10, and electrically connects a printed wiring board P (circuitsubstrate) to electrodes and interconnections formed on the first face10 a. The printed wiring board P is an external apparatus.

As shown in FIG. 1, a groove portion 11 is formed in a second face 10 bwhich is on a side opposite to the first face 10 a of the siliconsubstrate 10.

A bottom face of the groove portion 11 includes a rear face of a secondelectrode 23.

A conductive portion 12 is formed by filling the inside of grooveportion 11 with a conductive material.

An insulating film 13 is formed on side walls of the groove portion 11,and electrically insulates the conductive portion 12 from the siliconsubstrate 10.

A rear face insulating layer 14 is formed on a top face of the secondface 10 b of the silicon substrate 10 in regions other than a region onwhich the groove portion 11 is formed.

As shown in FIG. 3, rear face electrodes 15 (connection electrode) areformed on the rear face insulating layer 14, and corresponds toelectrodes of electronic elements, for example, surface acoustic wave(SAW) elements.

The connector 20 includes a foundation layer 21 formed on the first face10 a of the silicon substrate 10, a first electrode 22 and a secondelectrode 23 which are respectively formed in a plurality ofpredetermined regions of the foundation layer 21, a first insulatinglayer 24, and an interconnection section 30 formed on the firstinsulating layer 24.

The foundation layer 21 is formed from a conductive material such assilicon dioxide (SiO₂) and silicon nitride (Si₃N₄).

As materials of the first electrode 22 and the second electrode 23,titanium (Ti), titanium nitride (TiN), aluminum (Al), copper (Cu), or analloy of these can be used.

The first insulating layer 24 is formed on the silicon substrate 10,excepting the regions on which the first electrode 22 and the secondelectrode 23 are formed.

While a plurality of electrodes may be formed in the silicon substrate10 as shown in FIG. 2, only with respect to the first electrode 22 andthe second electrode 23 are explained in this embodiment.

The second electrode 23 may be covered by the first insulating layer 24.

An integrated circuit having a transistor and a memory element forexample, is formed under the foundation layer 21.

This integrated circuit is electrically connected to the first electrode22 and the second electrode 23.

As shown in FIGS. 1 and 2, the interconnection section 30 includes afirst interconnection 31 (interconnection), a metal film 32, a secondinsulating layer 33 (stress-absorbing layer), a second interconnection34 (interconnection), and a third insulating layer 35.

The first interconnection 31 (interconnection) is electrically connectedto the first electrode 22 formed on the first insulating layer 24.

The metal film 32 is formed on the top face of the second electrode 23.

The second insulating layer 33 (stress-absorbing layer) is formed overthe first interconnection (interconnection) 31 and the metal film 32.

The second interconnection (interconnection) 34 is formed on the secondinsulating layer 33 and electrically connected to the firstinterconnection 31.

The third insulating layer 35 is formed on the second interconnection34.

A part of the first interconnection 31 is exposed from the secondinsulating layer 33 to form a land section 36.

The land section 36 and the second interconnection 34 are electricallyconnected.

Moreover, a bump (external connection terminal) 37 is formed on thesecond interconnection 34, and the semiconductor device 1 iselectrically connected via this bump 37 to the printed wiring board P.

The third insulating layer 35 is formed on the second insulating layer33 and the second interconnection 34, excepting the region on which thebump 37 is formed.

The first electrode 22 is electrically connected to the bump 37 via thefirst interconnection 31 and the second interconnection 34.

The second electrode 23 is formed on the foundation layer 21 formed onthe first face 10 a of the silicon substrate 10.

A part of the rear face of the second electrode 23 forms the bottom faceof the groove portion 11.

Consequently, a rear face 23 a of the second electrode 23 and a firstend 12 a of the conductive portion 12 are electrically connected insidethe groove portion 11.

A second end 12 b of the conductive portion 12 is electrically connectedto the rear face electrode 15 formed in the second face 10 b of thesilicon substrate 10.

That is, the second electrode 23 is electrically connected to anelectronic element formed in the second face 10 b of the siliconsubstrate 10.

As examples of materials of the first interconnection 31 and the secondinterconnection 34, gold (Au), copper (Cu), titanium (Ti), tungsten (W),titanium-tungsten (TiW), titanium nitride (TiN), nickel (Ni), nickelvanadium (NiV), chrome (Cr), aluminum (Al), and palladium (Pd) can beused.

The structures of the first interconnection 31 and the secondinterconnection 34 may be single-layer structures of the above materialsor laminated structures combining multiple layers.

The first insulating layer 24, the second insulating layer 33, and thethird insulating layer 35 are formed from resin (synthetic resin).

Examples of materials for forming the first insulating layer 24, thesecond insulating layer 33, and the third insulating layer 35 can beused polyimide resin, silicon-modified polyimide resin, epoxy resin,silicon-modified epoxy resin, acrylic resin, phenol resin,benzocyclobutene (BCB), polybenzoxazole (PCB), or any material withinsulating properties.

The first insulating layer 24 may be formed from an insulating materialsuch as silicon dioxide (SiO₂) and silicon nitride (Si₃N₄).

It is preferable that the material of the metal film 32 be the same asthat of the first interconnection 31 and the second interconnection 34.

A metal such as Au, TiW, Cu, Cr, Ni, Ti, W, NiV, and Al can be used asthe material for the metal film 32.

The metal film 32 may be laminated from these metals.

It is preferable that the metal film 32 (at least one layer in the caseof a laminated structure) be formed from a material with higherresistance to corrosion than the electrode, such as Au, TiW, and Cr.

This prevents corrosion of the electrode and prevents generation ofelectrical malfunctions.

Manufacturing Method for Semiconductor Device

Subsequently, a manufacturing method for the semiconductor device 1 willbe explained while referring to FIGS. 4A to 5C.

In this embodiment, a plurality of the semiconductor devices 1 areformed simultaneously in one operation on a single silicon substrate 100(semiconductor substrate).

Each of the FIGS. 4A to 5C below describes the formation of onesemiconductor device 1.

Firstly, as shown in FIG. 4A, the foundation layer 21 is formed on thefirst face 10 a of the silicon substrate 10.

The first electrode 22 and the second electrode 23 are then formed onthe foundation layer 21.

The first insulating layer 24 is then formed on the first electrode 22and the second electrode 23, and insulating material covering the firstelectrode 22 and the second electrode 23 is removed by a conventionalmethod such as photolithography or etching.

It is not absolutely necessary to remove the insulating material whichcovers the second electrode 23.

Next, the first interconnection 31 is formed on the first insulatinglayer 24 including the first electrode 22, and the metal film 32 isformed on the top face of the second electrode 23.

The first interconnection 31 is formed by sequentially sputtering, forexample, TiW and Cu, and then plating the Cu.

The second insulating layer 33 is formed so as to cover the firstinterconnection 31 and the metal film 32.

The region corresponding to the land section 36 of the second insulatinglayer 33 is removed by a conventional photolithography method.

A part of the first interconnection 31 is thereby exposed, the landsection 36 is formed.

The second interconnection 34 is formed on the second insulating layer33 so as to connect to the land section 36.

The third insulating layer 35 is then formed so as to cover the secondinsulating layer 33 and the second interconnection 34, excepting theregion on which the bump 37 is formed on the second insulating layer 33and the second interconnection 34.

As shown in FIG. 4B, the sections of the silicon substrate 10 and thefoundation layer 21 that correspond to the second electrode 23, areremoved by dry etching of the second face 10 b of the silicon substrate10 using a photoresist 40 as a mask.

As shown in FIG. 4C, the groove portion 11 is formed by etching from thesecond face 10 b of the silicon substrate 10 to the rear face 23 a ofthe second electrode 23 formed on the first face 10 a.

In this embodiment, the photoresist 40 is used as a mask, there is nolimitation on this, for example an SiO₂ film may be used as a hard mark,or a photoresist and a hard mask may be used together.

The etching method is not limited to dry etching, it being acceptable touse wet etching, laser processing, or both of these.

Subsequently, as shown in FIG. 5A, the rear face insulating layer 14 andthe insulating film 13 are formed on the second face 10 b of the siliconsubstrate 10 and the inner walls of the groove portion 11.

The rear face insulating layer 14 and the insulating film 13 preventgeneration of current leakage, corrosion of the silicon substrate 10 dueto oxygen and water, and the similar.

As materials of the rear face insulating layer 14 and of the insulatingfilm 13, tetraethyl orthosilicate (Si(OC₂H₅) 4: hereinafter TEOS) formedby using plasma-enhanced chemical vapor deposition (PECVD), namelyPE-TEOS, and TEOS formed by using ozone CVD, namely O₃-TEOS, and silicondioxide (SiO₂) formed by using CVD, can be used.

Other insulating materials may be used for the rear face insulatinglayer 14 and the insulating film 13, even resin.

The insulating film 13 formed on the rear face 23 a of the secondelectrode 23 is removed by dry etching or laser processing to expose therear face 23 a of the second electrode 23 as shown in FIG. 5B.

The insulating film 13 remains on the side walls of the groove portion11.

The inside of the groove portion 11 is plated using an electrochemicalplating (ECP) method, a conductive material for forming the conductiveportion 12 is deposited on the inner sides of the groove portion 11, andthe first end 12 a of the conductive portion 12 is electricallyconnected to the exposed second electrode 23 on the rear face 23 a ofthe second electrode 23.

Copper (Cu), for example, is used as the conductive material for formingthe conductive portion 12.

Therefore, copper (Cu) is buried in the groove portion 11.

In this embodiment, the process of forming the conductive portion 12includes, for example, a process of sputtering (laminating) TiN and Cu,and a process of plating the Cu.

Alternatively, a process of sputtering (laminating) TiW and Cu, and aprocess of plating the Cu, may be included.

The method for forming the conductive portion 12 is not limited to thatmentioned above, a conductive paste, a molten metal, a metal wire, andthe similar may be buried.

The conductive portion 12 is buried inside the groove portion 11 in thisembodiment.

Instead of completely burying the conductive portion 12, the conductiveportion 12 may be formed on the inner walls of the groove portion 11 andbe electrically connected to the rear face 23 a of the second electrode23.

As shown in FIG. 5C, after forming the conductive portion 12, the rearface electrode 15 which electrically connected to the conductive portion12, is formed on the second face 10 b of the silicon substrate 10.

When forming the rear face electrode 15, simultaneously with theconductive portion 12 may be formed.

That is, the rear face electrode 15 and the conductive portion 12 may beformed in one operation.

The bump 37 includes a lead-free solder for example, and is formed onthe second interconnection 34 on the first face 10 a of the siliconsubstrate 10.

When forming the bump 37, a soldering ball may be packaged on the secondinterconnection 34 or a soldering paste may be printed onto the secondinterconnection 34.

By these processes, a plurality of semiconductor devices 1 can besimultaneously formed together on one silicon substrate 100.

As shown in FIG. 6, a dicing device divides each of the semiconductordevices 1 by cutting (dicing) the silicon substrate 100.

By forming the plurality of semiconductor devices 1 almostsimultaneously on the silicon substrate 100 and dicing the siliconsubstrate 100 into the individual semiconductor devices 1, a pluralityof the semiconductor device 1 as shown in FIG. 1 can be obtained.

In this manner, the semiconductor device 1 can be manufacturedefficiently and its manufacturing cost can be reduced.

According to the semiconductor device 1 of this embodiment, by formingthe conductive portion 12 inside the groove portion 11 as far as thesecond electrode 23, the second electrode 23 and the electronic elementcan be electrically connected via the conductive portion 12.

Since the first electrode 22 and the bump 37 are electrically connected,it is possible to make the semiconductor device 1, which can beconnected to external devices and the similar, small and thinner, andincrease its performance.

First Embodiment of Electronic Component

Subsequently, a first embodiment of an electronic component 50, in whichan electronic element including a SAW element 60 (electronic element) ispackaged on the semiconductor device 1, will be explained with referenceto FIG. 7.

In each of the embodiments described below, parts which are identicalwith the configuration of the semiconductor device 1 according to theembodiment described above are represented by identical referencenumerals and are not repetitiously explained.

A semiconductor device 51 used in the electronic component 50 of thisembodiment has the same configuration as the semiconductor device 1described above, excepting that the rear face electrode 15 is notprovided.

As shown in FIG. 8, the electronic component 50 includes a piezoelectricfilm and a fork-type electrode 61 which touches the piezoelectric film.

As shown in FIG. 7, the electronic component 50 is formed on the secondface 10 b of the silicon substrate 10.

The SAW element 60 is electrically connected to the second end 12 b ofthe conductive portion 12, and is formed directly on the second face 10b.

An integrated circuit including a transistor and a memory element, forexample, is formed on the first face 10 a of the silicon substrate 10.

The first end 12 a of the conductive portion 12 is electricallyconnected to this integrated circuit via the second electrode 23.

Therefore, the SAW element 60 formed on the second face 10 b of thesilicon substrate 10 is electrically connected via the conductiveportion 12 to the integrated circuit formed on the first face 10 a ofthe silicon substrate 10.

The electronic component 50 includes a sealing member 52.

By arranging the SAW element 60 between the sealing member 52 and thesecond face 10 b of the silicon substrate 10, the SAW element 60 issealed.

While in this embodiment the sealing member 52 is made of a glasssubstrate, a silicon substrate may be used.

The sealing member 52 is spaced from the second face 10 b of the siliconsubstrate 10.

The peripheral edge of the second face 10 b of the silicon substrate 10is affixed to the peripheral edge of an inner face 52 a of the sealingmember 52 by an adhesive layer 53.

For example, a synthetic resin such as polyimide resin can be used asthe material of the adhesive layer 53.

An internal space 55 enclosed by the second face 10 b of the siliconsubstrate 10, the inner face 52 a of the sealing member 52, and theadhesive layer 53 is substantially sealed (by an airtight seal), and theSAW element 60 is arranged in the internal space 55.

Manufacturing Method for Electronic Component

Subsequently, a method for manufacturing the electronic component 50will be explained.

By performing a process similar to the method for manufacturing thesemiconductor device 1 described above, the conductive portion 12 isformed, and the SAW element 60 is then formed on the second face 10 b ofthe silicon substrate 10.

The process of forming this SAW element 60 includes a process of forminga piezoelectric film, a process of forming a fork-type electrode 61touching the piezoelectric film such as shown in FIG. 8, and a processof forming a protective film.

In addition, the process of forming the SAW element 60 includes aprocess of irradiating plasma or the similar onto the SAW element 60 andadjusting the frequency.

As examples of materials used for the piezoelectric film, zinc oxide(ZnO), aluminum nitride (AlN), lithium niobate (LiNbO₃), lithiumtantalate (LiTaO₃), and potassium niobate (KNbO₃) can be used.

As a material of the fork-type electrode 61, a metal including aluminumcan be used.

As the material of the protective film, Silicon dioxide (SiO₂), siliconnitride (Si₃N₄), titanium nitride (TiN), and the similar, may be used.

The SAW element 60 thus formed is electrically connected to the secondend 12 b of the conductive portion 12 on the second face 10 b of thesilicon substrate 10.

An adhesive for forming the adhesive layer 53 is provided on at leastone of the second face 10 b of the silicon substrate 10 and the innerface 52 a of the sealing member 52.

A photosensitive polyimide adhesive or the similar can be used as theadhesive layer 53.

The silicon substrate 10 and the sealing member 52 are connectedtogether with the second face 10 b of the silicon substrate 10 and theinner face 52 a of the sealing member 52 facing each other on oppositesides of this adhesive layer 53.

This obtains the electronic component 50 as shown in FIG. 7.

The structure for sealing the SAW element 60 may be a vacuum sealachieved by making the internal space 55 a vacuum, a gas replacementseal achieved by replacing the atmosphere of the internal space 55 witha predetermined gas such as N₂, Ar, and He, and the similar.

When connecting the silicon substrate 10 and the sealing member 52,metal protrusions may be formed along the peripheral edge of the secondface 10 b of the silicon substrate 10, and a metal layer for affixingthe metal protrusions may be formed on the inner face 52 a of thesealing member 52, the silicon substrate 10 and the sealing member 52may be connected together via these metal protrusions and the metallayer.

When a permeable glass is used as the sealing member 52, after thesealing process, the frequency of the SAW element 60 can be adjusted bytransmitting a laser or the similar through the glass.

The bump made of a lead-free solder for example, is then packaged on thesecond interconnection 34 formed on the first face 10 a of the siliconsubstrate 10.

When forming the bump 37, a soldering ball may be packaged on the secondinterconnection 34 or a soldering paste may be printed onto the secondinterconnection 34.

In the manufacturing method of this electronic component 50, in the samemanner as the manufacturing method of the semiconductor device 1, theelectronic component 50, the SAW element 60, the sealing member 52, andso on, are simultaneously formed together on the same silicon substrate(semiconductor substrate).

The electronic component 50 is obtained by dividing individualelectronic components 50 by using a dicing device 110 as in themanufacturing method of the semiconductor device 1.

This enables the electronic component 50 to be manufacturedinexpensively.

The manufactured electronic component 50 is packaged via the bump 37 ona printed wiring board P or the similar.

In the electronic component 50 according to this embodiment, the SAWelement 60 is formed on the second face 10 b of the silicon substrate 10and the second end 12 b of the conductive portion 12 is connected tothis SAW element 60.

In this case, by providing an integrated circuit for driving and forcontrolling the SAW element 60 on the first face. 10 a of the siliconsubstrate. 10, the SAW element 60 can be electrically connected to theintegrated circuit via the conductive portion 12.

Therefore, the overall electronic component 50 can be made smaller andthinner while reliably sealing and driving the SAW element 60.

In addition, since SAW element 60 is sealed between the sealing member52 and the second face 10 b, it is possible to realize smaller andthinner, to seal the SAW element 60, and to drive the SAW element 60.

Second Embodiment of Electronic Component

Subsequently, a second embodiment of an electronic component 70, inwhich an electronic element including a SAW element 71 is packaged onthe semiconductor device 1 described above will be explained withreference to FIG. 9.

In each of the embodiments described below, parts which are identicalwith the configuration of the semiconductor device 1 according to theabove mentioned first embodiment are represented by identical referencenumerals and are not repetitiously explained.

The electronic component 70 of this embodiment differs from that of thefirst embodiment in that, instead of forming the SAW element 71 on thesecond face 10 b of the silicon substrate 10, the SAW element 71 isformed on the sealing member 52 which is spaced and is arrangedseparately from the second face 10 b of the silicon substrate 10.

The SAW element 71 is formed on the inner face 52 a (facing face) of thesealing member 52.

The inner face 52 a is faced to the second face 10 b of the siliconsubstrate 10.

The SAW element 71 includes a terminal 72 facing the second face 10 b ofthe silicon substrate 10.

In a semiconductor device 73, a rear face electrode 54 (connectionelectrode) is formed above the groove portion 11 in the second face 10 bof the silicon substrate 10.

The rear face electrode 54 is electrically connected to the second end12 b of the conductive portion 12.

The rear face electrode 54 is formed at a position corresponding to theterminal 72 of the SAW element 71.

That is, the second electrode 23 is electrically connected to the SAWelement 71 formed on the inner face (facing face) 52 a of the sealingmember 52 via the conductive portion 12 and the rear face electrode 54.

The sealing member 52 is, for example, a silicon substrate, a crystalsubstrate, and a substrate including silicon and diamond.

A method for manufacturing the electronic component 70 will beexplained.

Firstly, the SAW element 71 is formed beforehand on the inner face 52 aof the sealing member 52.

The rear face electrode 54 is formed on the second face 10 b of thesilicon substrate 10.

The terminal 72 is also formed.

The silicon substrate 10 and the sealing member 52 are then connectedvia the adhesive layer 53 such that the rear face electrode 54 iselectrically connected to the terminal 72.

This obtains the electronic component 70 as shown in FIG. 9.

In the process of connecting the rear face electrode 54 to the terminal72, they may be pressed together by compressing the adhesive layer 53.

According to the electronic component 70 of this embodiment, since theSAW element 71 is formed on the sealing member 52 as a separate memberfrom the silicon substrate 10, the SAW element 71 is less liable to beaffected by thermal stress and film stress applied to the siliconsubstrate 10, obtaining superior characteristics.

Third Embodiment of Electronic Component

Subsequently, a third embodiment of an electronic component 80, in whichan electronic element including a SAW element 81 is packaged on thesemiconductor device 1 described above will be explained with referenceto FIG. 10.

The electronic component 80 according to this embodiment differs fromthe second embodiment in that, instead of forming the SAW element 81 onthe second face 10 b of the silicon substrate 10, the SAW element 81 isformed on a supporting substrate 82.

The supporting substrate 82 is arranged between the second face 10 b ofthe silicon substrate 10 and the sealing member 52 which is spaced fromthe second face 10 b of the silicon substrate 10.

The SAW element 81 is formed on a face 82 a of the supporting substrate82 facing the second face 10 b of the silicon substrate 10.

Moreover, a terminal 83 is formed on the SAW element 81 and faces thesecond face 10 b of the silicon substrate 10 in the same manner as theelectronic component 70 of the second embodiment.

This terminal 83 is electrically connected to the rear face electrode54.

According to the electronic component 80 of this embodiment, since theSAW element 81 is formed on the supporting substrate 82 which is aseparate member from the silicon substrate 10, the SAW element 81 isless liable to be affected by thermal stress and film stress applied tothe silicon substrate 10, obtaining superior characteristics.

The supporting substrate 82 reliably supports the SAW element 81, it ispossible to electrically connect the SAW element 81 to the conductiveportion 12.

Fourth Embodiment of Electronic Component

Subsequently, a fourth embodiment of an electronic component 90, inwhich an electronic element including an AT oscillator (liquid crystaloscillator) 91 is packaged on the semiconductor device 1 will beexplained with reference to FIG. 11.

The electronic component 90 of this embodiment differs from that of thesecond embodiment in that the AT oscillator 91 is sealed by a sealingmember 93 while being supported by a supporting substrate 92.

The supporting substrate 92 is spaced and is arranged separately fromthe second face 10 b of the silicon substrate 10.

The AT oscillator 91 is formed on an inner face 92 a of the supportingsubstrate 92 facing the second face 10 b of the silicon substrate 10.

The AT oscillator 91 is sealed by the sealing member 93 made of a glasssubstrate which is provided between the supporting substrate 92 and thesecond face 10 b of the silicon substrate 10.

An internal space 95 is enclosed by the inner face 92 of the supportingsubstrate 92 and an inner face 93 a of the sealing member 93, and sealedin an substantially airtight seal.

An electronic element electrode 94 is provided on a face of the sealingmember 93 which faces the second face 10 b of the silicon substrate 10.

The electronic element electrode 94 covers the sealing member 93.

The electronic element electrode 94 and the rear face electrode 54 areelectrically connected.

That is, the second electrode 23 is electrically connected to the AToscillator 91 via the conductive portion 12 formed on the siliconsubstrate 10 and the rear face electrode 54 formed on the second face 10b of the silicon substrate 10.

The peripheral edge of the second face 10 b of the silicon substrate 10and the peripheral edge of the supporting substrate 92 are sealed with asealing resin 96.

The space between the second face 10 b and the sealing member 93 issealed by the sealing resin 96.

According to the electronic component 90 of this embodiment, since theAT oscillator is supported by the supporting substrate 92 and sealed bythe sealing member 93, the electronic element electrode 94 formed on thesealing member 93 can be electrically connected to the conductiveportion 12.

This enables the electronic element to be made smaller and thinner, anddrive reliably.

Electronic Apparatus

FIG. 12 is one example of an electronic apparatus including any one ofthe above mentioned electronic components 50, 70, 80, and 90, is a viewof a mobile telephone 300.

By packaging the electronic components of this invention, which are madesmaller and thinner while increasing their performance, the mobiletelephone 300 can be miniaturized.

The embodiments of the invention described above are not limited, it ispossible to make various modifications without departing from the spiritor scope of the invention.

For example, while the embodiment of the semiconductor device 1described above includes the rear face electrode 15, the electrode ofthe electronic component may be connected directly to the second end 12b of the conductive portion 12.

To facilitate the metal connections, the top faces of the rear faceelectrodes 15 and 54 connected to the SAW elements 60, 71 and 81 and theAT oscillator 91, or the top face of the second end 12 b of theconductive portion 12, may be processed with metal or plated with abrazing filler metal (e.g., SnAg plating).

In each of the above embodiments, in addition to the final process ofdicing, the individual electronic components may be obtained by otherappropriate processes (intermediate steps).

Moreover, when glass substrates are used as the sealing members 52 and93, while the sealing members 52 and 93 consisting of these glasssubstrates can be diced (cut) by the dicing device 110 described in FIG.6, they can also be diced by laser irradiation, or by another dicingmethod using dry etching or wet etching.

While SAW elements are described as electronic elements of thisinvention in the first embodiment, the second embodiment, and the thirdembodiment, this is not limitative of the invention, and any elementwhich requires a sealed structure can be used, e.g., crystaloscillators, piezoelectric oscillators, and piezoelectric tuning-forks.

While the fourth embodiment describes an AT oscillator (liquid crystaloscillator), this is not limitative of the invention, and any elementwhich requires a sealed structure can be used, e.g., a SAW element, apiezoelectric oscillator, and a piezoelectric tuning-fork.

If necessary, the silicon substrate 10 may be thinned after forming theinterconnection section 30 on it.

A method for thinning the silicon substrate 10 will be explained.

Firstly, an unillustrated glass plate is affixed to the first face 10 aside of the silicon substrate 10 using an adhesive which can be peeledaway by irradiation of ultraviolet light (UV light).

This glass plate is part of what is termed a wafer support system (WSS),and, after supporting the silicon substrate 10 on the glass plate, thesecond face 10 b of the silicon substrate 10 is processed by polishing,dry or wet etching, and so on, with the glass plate still affixed to it.

This enables the silicon substrate 10 to be made thin.

1. A semiconductor device comprising: a semiconductor substrateincluding a first face and a second face on a side opposite to the firstface; an external connection terminal formed on the first face of thesemiconductor substrate; a first electrode formed on the first face ofthe semiconductor substrate and electrically connected to the externalconnection terminal; an electronic element formed on or above the secondface of the semiconductor substrate; a second electrode formed on thefirst face of the semiconductor substrate, electrically connected to theelectronic element, and having a top face and a rear face; a grooveportion formed on the second face of the semiconductor substrate andhaving a bottom face including at least part of the rear face of thesecond electrode; and a conductive portion formed in the groove portionand electrically connected to the rear face of the second electrode. 2.The semiconductor device according to claim 1, further comprising: aninterconnection formed on the first face of the semiconductor substrateand electrically connected to the first electrode and the externalconnection terminal; and a stress-absorbing layer formed between thesemiconductor substrate and the external connection terminal.
 3. Thesemiconductor device according to claim 1, further comprising: a metalfilm formed on the top face of the second electrode and including anidentical material of the interconnection.
 4. The semiconductor deviceaccording to claim 1, further comprising: a connection electrode formedon the second face of the semiconductor substrate and electricallyconnected to the conductive portion.
 5. An electronic componentcomprising: a semiconductor substrate including a first face and asecond face on a side opposite to the first face; an external connectionterminal formed on the first face of the semiconductor substrate; afirst electrode formed on the first face of the semiconductor substrateand electrically connected to the external connection terminal; anelectronic element formed on or above the second face of thesemiconductor substrate; a second electrode electrically connected tothe electronic element and having a top face and a rear face; a grooveportion formed on the second face of the semiconductor substrate andhaving a bottom face including at least part of the rear face of thesecond electrode; a conductive portion formed in the groove portion andelectrically connected to the rear face of the second electrode; and asealing member sealing the electronic element.
 6. The electroniccomponent according to claim 5, wherein the sealing member is spacedfrom the second face of the semiconductor substrate, and includes afacing face facing the second face of the semiconductor substrate, andthe electronic element is formed on the facing face.
 7. The electroniccomponent according to claim 5, further comprising: a supportingsubstrate supporting the electronic element, wherein the sealing memberis spaced from the second face of the semiconductor substrate, and thesupporting substrate is arranged between the sealing member and thesemiconductor substrate.
 8. The electronic component according to claim5, further comprising: a supporting substrate spaced from the secondface of the semiconductor substrate and supporting the electronicelement, wherein the sealing member seals the electronic elementsupported by the supporting substrate and includes an electronic elementelectrode electrically connected to the electronic element.
 9. Theelectronic component according to claim 5, further comprising: aconnection electrode formed on the second face of the semiconductorsubstrate and electrically connecting the conductive portion to theelectronic element.
 10. A circuit substrate on which the electroniccomponent according to claim 5 is packaged.
 11. An electronic apparatusin which the electronic component according to claim 5 is packaged.